JPS6331848Y2 - - Google Patents

Abstract

A drilling tool including a central, laterally flattened primary drill adapted to produce a cylindrical main drillhole and a secondary drill, pivotally displaceable relative to the primary drill, in a laterally outward direction to produce an undercut, a sleeve which concentrically surrounds the primary drill and is axially slidable on the shaft of the primary drill against the action of a spring and a slotted link system adapted to effect pivoting of the secondary drill relative to the primary drill. The sleeve is constructed as a cage having a rear portion adapted to guide it for axial movement along the shaft, webs extend from the rear portion in the general direction of the shaft axis and leave large passages in the axial and circumferential direction, and an end ring joins the webs at their outer ends.

Description

[Detailed description of the invention] The invention consists of a flat main drilling body for drilling a cylindrical main hole, and a pair of cutting members that can swing relative to the main drilling body through a slot. The secondary drilling body is displaceable in the axial direction of the main drilling body against the spring force, and is capable of swinging laterally for chamfering. In other words, it relates to a drilling tool for machining a hole that is wide at the back.

A drilling tool of the above type used for drilling holes in bedrock, hard stones, etc. is known, for example, from German Patent Publication No. 2331467 (corresponding to Japanese Patent Application Laid-open No. 76680/1983). A hole drilled using this known drilling tool has a cross-sectional shape that widens into a conical shape as it goes deeper into the hole, and is used to fix an anchor for connecting to a member to be fixed. used for. For anchoring in hard rock or stone, force-fitting of radially expandable nails is generally sufficient; for lightweight construction materials, form-fitting conical anchors are preferred. It has been proven that.

The drilling tools known from DE 2331467 and JP 50-76680 are unsuitable for practical use in various respects. In particular, the main drilling body is conical and sharp, and the secondary drilling body is provided only on one side, and the cutting edge is only a short length. Can not do it. This is particularly disadvantageous when drilling lightweight construction materials. With this configuration, removal of cutting debris is also not possible in the case of hard stones.

The basic object of the present invention is to provide a drilling tool that has excellent functionality for drilling holes in wall materials such as the above-mentioned lightweight construction materials, especially aerated concrete.

This object is achieved in the present invention by using the features of the registered claims.

With this configuration, when the sleeve-shaped cage is abutted against the wall surface to be drilled, the blades of the main drilling body are aligned in a horizontal straight line, the secondary drilling body is well-balanced and composed of a pair of cutting members, and since the cage has an opening, this, combined with the rotation of the internal symmetrical cutting blades, forms a sufficiently large discharge path leading to the outside, allowing the cutting chips to be discharged to the outside without the sleeve-shaped cage storing them.

In this case, the front edge of the cage in the drilling direction, which has the role of abutting the sleeve-like cage on the workpiece, is formed to be rotatable relative to other parts, and the outer periphery of the base of the cage is connected to the legs and the surrounding ring. At the same time, by forming the cage to be rotatable relative to the inner circumferential ring of the base, the functionality of the cage (and thus the entire drilling tool), particularly the ability to discharge cutting waste, can be further improved. For this reason, a bearing is arranged between the outer circumferential portion and the inner circumferential ring.

The main perforator is formed by a plate-shaped countersunk sawmill having a sharp point in the center and blades extending in the radial direction on both sides. In that case, by providing a suitable forward inclination of the cutting edge, it exhibits the function of discharging the cuttings rearwardly relative to the sleeve-like cage, similar to a rotary pump.

The auxiliary perforation body is arranged symmetrically on both sides of the main perforation body, and is made by cutting members made of two plates that can swing so that the bottom side opens outward like the hem of a skirt. Form. in this case,
Since the main perforation body is a flat plate, there is no problem in arranging the two plates forming the sub-puncture body on the sides, and the sub-puncture body is guided within the slit of the main perforation body. There is no risk of the pressing of the auxiliary punching body against the main punching body due to cutting waste, which is the case with the conventional punching tool described above. By holding the pair of plates that form the sub-drilling body diametrically opposed to each other, it satisfies the requirement for symmetry as a drilling tool, and is compared to a device with a swingable sub-drilling body on one side. This allows for cleaner drilling.

The present invention will be explained below with reference to the drawings.

A main drilling body in the shape of a core drill (countersunk) 3 is fixed to the central shaft 1 of a drilling tool which can be clamped and fixed to the shaft 2 of a drilling machine. As shown more clearly in FIG. 2, this main perforation body is made of a relatively thin plate material that is approximately rectangular and has a slightly narrower width on the rear side when viewed in the perforation direction. The main perforator has a central cusp 4 at the center of its front end and blades 5 extending radially from both sides thereof and slightly inclined forward as shown in FIG.

A blade plate 6 is attached to each of the large and flat sides of the countersunk massager 3, which can swing around the shaft of a bolt 7 passing through the countersunk massager 3.
These blade plates 6 are capable of swinging outward in opposite directions to each other in the directions shown by arrows 8.
Together, they form a sub-perforated body. In the rest or non-use condition shown in FIG.
0 is set. This blade 10 has a cross-sectional shape similar to that of the blade 5 of the main perforator, and its front end corner 11
is formed diagonally.

A cage-shaped cage 12 is guided and supported so as to be feedable in the direction of the central axis 9 of the main shaft 1. The cage 12 is pressed by a pressing spring 13 as shown in the rest state in FIG. The cage 12 consists of a base 14, three legs (webs) 15 arranged at equal angular intervals around its periphery, and a peripheral ring 16 (webs) connected to its free end and facing the working area of the drilling tool. (see Figure 3). This cage 12 is advantageously made of synthetic resin. Base 14 of cage 12
consists of an outer rim part 17 and an inner ring 19, and the outer rim part 17 supports the leg part 15 and supports the inner ring 1 by a ball bearing 18.
It is rotatable relative to 9.

Inside the inner ring 19 of the cage 12, a large number of small balls 20 are arranged at appropriate angular intervals so that the cage 12 can be easily displaced in the axial direction with respect to the axis 1. In order to advance the inner circumferential ring 19 within the cage into the drilling area of the drilling tool, the inner circumferential ring 19 is provided with arms 21 extending substantially parallel to each side of the main drilling body. The free ends of these arms 21 are connected by pins 22 passing through elongated holes 23 provided in the main bore 3, so that their displacement is prevented against the spring 13 in the direction of the central axis 1 of the cage 12. It has a unique structure.

The pin 22 is attached to a blade plate 6 forming a sub-boring body.
form the node of the slotted link guide that guides the outward swing of the For this purpose, the cutter plate 6 is provided with a slit 24 which extends in a direction oblique to the central axis 9 in the rest state of the sub-drilling body. Now, when the cage 12 is slid upward in FIG. The end (tip) is arrow 8
It rotates in the outward direction shown by .

The embodiment shown in FIGS. 4 and 5 differs from the previous embodiment in the structure and rotation mechanism of the sub-boring body.
The pin 22 that connects the arm 21 of the cage 12 is
Here, a rotation axis for the blade plate 6 supported by the pin 22 is formed. Therefore, in this case, the pin 22 only passes through the long groove 28 provided in the main perforated body 3. The main perforated body 3 further supports a pin 25 on its center line, and this pin 25 is inserted into a slit 24 provided in the blade plate 6 and extending in a direction oblique to the main axis 9, and is inserted into the connecting link guide. functions as a node.

Instead of the first embodiment, in this embodiment the knife plate 6 is formed approximately L-shaped and has a blade 10 parallel to the slit 24. In this case, it is possible to obtain a cylindrical undercut hole, rather than a conical undercut hole as in the first embodiment, that is, a hole that is tight at the mouth and widens into a cylindrical shape at the back.

As is clear from the above description, the intended purpose can be effectively achieved by using the punching tool of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional side view of a drilling tool according to the present invention, FIG. 2 is a partial cross-sectional side view of the drilling tool of FIG. 1 as seen from a direction different by 90° around the main shaft, and FIG.
FIG. 4 is a partial cross-sectional side view of another embodiment of the punching tool of the present invention, corresponding to FIG. 1; FIG. 5 is a second embodiment of the punching tool shown in FIG.
FIG. 1 is a partial cross-sectional view corresponding to the figure. 1: shaft, 3: main perforator, 4: central tip, 5: blade, 6: secondary perforator, 10: blade, 1
2... cage, 14... base, 15... legs, 16
...peripheral ring, 17...outer periphery, 18...bearing, 19...inner ring, 21...arm,
22...pin, 24...slit.

Claims (1)

[Claims for Utility Model Registration] A rotatable drive shaft extending in the axial direction; a substantially flat plate-shaped main boring body fixed to one end of the drive shaft and extending in the axial direction of the drive shaft; has
A front end of the main bore extends radially outwardly from the axis, such that the front end forms cutting edges extending radially outward at right angles to the axis on either side of the axis; the body has a pair of opposing surfaces, each surface having a pair of spaced apart edges each extending axially on opposite sides of the axis of the drive shaft; It has a sub-boring body composed of a pair of cutting members pivotally connected to the main boring body, and these pair of cutting members are located rearward in the axial direction from the cutting edge of the main boring body. mutually opposite positions between a retracted position, inboard of the axially extending edge of the main perforation, and an expanded position, such as widening the skirt, radially outward of the axially extending edge of the face of this main perforation. The pair of cutting members are each pivotably mounted for symmetrical pivoting in the direction, and each of the pair of cutting members in the extended position is located axially rearwardly of the cutting edge of the main boring body and radially outwardly of the main boring body. spring means having a cutting edge extending for a considerable length in the axial direction of the position and urging the secondary drilling body into a retracted position; and overcoming the spring means only after the drilling tool has advanced a predetermined distance in the axial direction. , a spring force overcoming means for bringing the pair of cutting members to an expanded position to form an undercut, the spring force overcoming means being concentric with the drive shaft, surrounding the drive shaft, and extending relative to the drive shaft. a sleeve-like cage adapted to be axially movable, the cage having a sleeve-like cage that is movable in the axial direction, and the cage is configured to move the cutting members within the axially extending region of the cage when the pair of cutting members are in the retracted position. The slots are movable relative to each other in the axial direction, and in the retracted position of the cutting member, the first and second slots are arranged so that the first end of the main boring body is located closer to the cutting edge of the main boring member. and a second end disposed further from the first end, each of the first ends being located on the axis of the drive shaft, and each of the second ends being spaced apart in a radial direction from the axis of the drive shaft. located outside the
For this purpose, the first and second slots are arranged symmetrically apart from each other at an angle to the axis of the main boring body when viewed from the cut edge thereof, and furthermore, the first and second slots are arranged symmetrically apart from each other at an angle with respect to the axis of the main boring body, and furthermore, the first and second slots are arranged in the main boring body so as to extend along the axis of the drive shaft. a third slot, and pins passing through the first, second and third slots, and means for securing the pins to the cage; and said spring means is adapted to hold said sleeve-like cage in a manner that allows the cutting of the main bore. A cutting member that has a spring that presses in the axial direction toward the edge, has a cone-shaped cutting edge that extends symmetrically to the left and right of the main perforation body, and can spread symmetrically to the left and right of the sub-puncture body like the hem of a skirt. 1. A drilling tool for forming an undercut hole, characterized in that the drilling tool has a shape such that cutting chips are carried out of the cutting hole by interaction of the cutting edges of the hole.